When Do Nutrients in Food Expire?

Find out which nutrition benefits of some foods may decrease with time.

Sometimes there are clues when a food passes its prime: lettuce wilts, bananas turn brown. Other foods will look and smell OK long after their health punch has dramatically declined. “Certain nutrients are unstable when exposed to oxygen (from the air), heat (from cooking) and light,” says Carol Johnston, Ph.D., R.D., chair of the Department of Nutrition at Arizona State University. Keep track of how long you store the following nutrient-rich foods.